xref: /openbmc/linux/drivers/clk/at91/sckc.c (revision 61bf3293) 
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * drivers/clk/at91/sckc.c
4  *
5  *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
6  */
7 
8 #include <linux/clk-provider.h>
9 #include <linux/clkdev.h>
10 #include <linux/delay.h>
11 #include <linux/of.h>
12 #include <linux/of_address.h>
13 #include <linux/io.h>
14 
15 #define SLOW_CLOCK_FREQ		32768
16 #define SLOWCK_SW_CYCLES	5
17 #define SLOWCK_SW_TIME_USEC	((SLOWCK_SW_CYCLES * USEC_PER_SEC) / \
18 				 SLOW_CLOCK_FREQ)
19 
20 #define	AT91_SCKC_CR			0x00
21 
22 struct clk_slow_bits {
23 	u32 cr_rcen;
24 	u32 cr_osc32en;
25 	u32 cr_osc32byp;
26 	u32 cr_oscsel;
27 };
28 
29 struct clk_slow_osc {
30 	struct clk_hw hw;
31 	void __iomem *sckcr;
32 	const struct clk_slow_bits *bits;
33 	unsigned long startup_usec;
34 };
35 
36 #define to_clk_slow_osc(hw) container_of(hw, struct clk_slow_osc, hw)
37 
38 struct clk_sama5d4_slow_osc {
39 	struct clk_hw hw;
40 	void __iomem *sckcr;
41 	const struct clk_slow_bits *bits;
42 	unsigned long startup_usec;
43 	bool prepared;
44 };
45 
46 #define to_clk_sama5d4_slow_osc(hw) container_of(hw, struct clk_sama5d4_slow_osc, hw)
47 
48 struct clk_slow_rc_osc {
49 	struct clk_hw hw;
50 	void __iomem *sckcr;
51 	const struct clk_slow_bits *bits;
52 	unsigned long frequency;
53 	unsigned long accuracy;
54 	unsigned long startup_usec;
55 };
56 
57 #define to_clk_slow_rc_osc(hw) container_of(hw, struct clk_slow_rc_osc, hw)
58 
59 struct clk_sam9x5_slow {
60 	struct clk_hw hw;
61 	void __iomem *sckcr;
62 	const struct clk_slow_bits *bits;
63 	u8 parent;
64 };
65 
66 #define to_clk_sam9x5_slow(hw) container_of(hw, struct clk_sam9x5_slow, hw)
67 
68 static int clk_slow_osc_prepare(struct clk_hw *hw)
69 {
70 	struct clk_slow_osc *osc = to_clk_slow_osc(hw);
71 	void __iomem *sckcr = osc->sckcr;
72 	u32 tmp = readl(sckcr);
73 
74 	if (tmp & (osc->bits->cr_osc32byp | osc->bits->cr_osc32en))
75 		return 0;
76 
77 	writel(tmp | osc->bits->cr_osc32en, sckcr);
78 
79 	if (system_state < SYSTEM_RUNNING)
80 		udelay(osc->startup_usec);
81 	else
82 		usleep_range(osc->startup_usec, osc->startup_usec + 1);
83 
84 	return 0;
85 }
86 
87 static void clk_slow_osc_unprepare(struct clk_hw *hw)
88 {
89 	struct clk_slow_osc *osc = to_clk_slow_osc(hw);
90 	void __iomem *sckcr = osc->sckcr;
91 	u32 tmp = readl(sckcr);
92 
93 	if (tmp & osc->bits->cr_osc32byp)
94 		return;
95 
96 	writel(tmp & ~osc->bits->cr_osc32en, sckcr);
97 }
98 
99 static int clk_slow_osc_is_prepared(struct clk_hw *hw)
100 {
101 	struct clk_slow_osc *osc = to_clk_slow_osc(hw);
102 	void __iomem *sckcr = osc->sckcr;
103 	u32 tmp = readl(sckcr);
104 
105 	if (tmp & osc->bits->cr_osc32byp)
106 		return 1;
107 
108 	return !!(tmp & osc->bits->cr_osc32en);
109 }
110 
111 static const struct clk_ops slow_osc_ops = {
112 	.prepare = clk_slow_osc_prepare,
113 	.unprepare = clk_slow_osc_unprepare,
114 	.is_prepared = clk_slow_osc_is_prepared,
115 };
116 
117 static struct clk_hw * __init
118 at91_clk_register_slow_osc(void __iomem *sckcr,
119 			   const char *name,
120 			   const char *parent_name,
121 			   unsigned long startup,
122 			   bool bypass,
123 			   const struct clk_slow_bits *bits)
124 {
125 	struct clk_slow_osc *osc;
126 	struct clk_hw *hw;
127 	struct clk_init_data init;
128 	int ret;
129 
130 	if (!sckcr || !name || !parent_name)
131 		return ERR_PTR(-EINVAL);
132 
133 	osc = kzalloc(sizeof(*osc), GFP_KERNEL);
134 	if (!osc)
135 		return ERR_PTR(-ENOMEM);
136 
137 	init.name = name;
138 	init.ops = &slow_osc_ops;
139 	init.parent_names = &parent_name;
140 	init.num_parents = 1;
141 	init.flags = CLK_IGNORE_UNUSED;
142 
143 	osc->hw.init = &init;
144 	osc->sckcr = sckcr;
145 	osc->startup_usec = startup;
146 	osc->bits = bits;
147 
148 	if (bypass)
149 		writel((readl(sckcr) & ~osc->bits->cr_osc32en) |
150 					osc->bits->cr_osc32byp, sckcr);
151 
152 	hw = &osc->hw;
153 	ret = clk_hw_register(NULL, &osc->hw);
154 	if (ret) {
155 		kfree(osc);
156 		hw = ERR_PTR(ret);
157 	}
158 
159 	return hw;
160 }
161 
162 static void at91_clk_unregister_slow_osc(struct clk_hw *hw)
163 {
164 	struct clk_slow_osc *osc = to_clk_slow_osc(hw);
165 
166 	clk_hw_unregister(hw);
167 	kfree(osc);
168 }
169 
170 static unsigned long clk_slow_rc_osc_recalc_rate(struct clk_hw *hw,
171 						 unsigned long parent_rate)
172 {
173 	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
174 
175 	return osc->frequency;
176 }
177 
178 static unsigned long clk_slow_rc_osc_recalc_accuracy(struct clk_hw *hw,
179 						     unsigned long parent_acc)
180 {
181 	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
182 
183 	return osc->accuracy;
184 }
185 
186 static int clk_slow_rc_osc_prepare(struct clk_hw *hw)
187 {
188 	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
189 	void __iomem *sckcr = osc->sckcr;
190 
191 	writel(readl(sckcr) | osc->bits->cr_rcen, sckcr);
192 
193 	if (system_state < SYSTEM_RUNNING)
194 		udelay(osc->startup_usec);
195 	else
196 		usleep_range(osc->startup_usec, osc->startup_usec + 1);
197 
198 	return 0;
199 }
200 
201 static void clk_slow_rc_osc_unprepare(struct clk_hw *hw)
202 {
203 	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
204 	void __iomem *sckcr = osc->sckcr;
205 
206 	writel(readl(sckcr) & ~osc->bits->cr_rcen, sckcr);
207 }
208 
209 static int clk_slow_rc_osc_is_prepared(struct clk_hw *hw)
210 {
211 	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
212 
213 	return !!(readl(osc->sckcr) & osc->bits->cr_rcen);
214 }
215 
216 static const struct clk_ops slow_rc_osc_ops = {
217 	.prepare = clk_slow_rc_osc_prepare,
218 	.unprepare = clk_slow_rc_osc_unprepare,
219 	.is_prepared = clk_slow_rc_osc_is_prepared,
220 	.recalc_rate = clk_slow_rc_osc_recalc_rate,
221 	.recalc_accuracy = clk_slow_rc_osc_recalc_accuracy,
222 };
223 
224 static struct clk_hw * __init
225 at91_clk_register_slow_rc_osc(void __iomem *sckcr,
226 			      const char *name,
227 			      unsigned long frequency,
228 			      unsigned long accuracy,
229 			      unsigned long startup,
230 			      const struct clk_slow_bits *bits)
231 {
232 	struct clk_slow_rc_osc *osc;
233 	struct clk_hw *hw;
234 	struct clk_init_data init;
235 	int ret;
236 
237 	if (!sckcr || !name)
238 		return ERR_PTR(-EINVAL);
239 
240 	osc = kzalloc(sizeof(*osc), GFP_KERNEL);
241 	if (!osc)
242 		return ERR_PTR(-ENOMEM);
243 
244 	init.name = name;
245 	init.ops = &slow_rc_osc_ops;
246 	init.parent_names = NULL;
247 	init.num_parents = 0;
248 	init.flags = CLK_IGNORE_UNUSED;
249 
250 	osc->hw.init = &init;
251 	osc->sckcr = sckcr;
252 	osc->bits = bits;
253 	osc->frequency = frequency;
254 	osc->accuracy = accuracy;
255 	osc->startup_usec = startup;
256 
257 	hw = &osc->hw;
258 	ret = clk_hw_register(NULL, &osc->hw);
259 	if (ret) {
260 		kfree(osc);
261 		hw = ERR_PTR(ret);
262 	}
263 
264 	return hw;
265 }
266 
267 static void at91_clk_unregister_slow_rc_osc(struct clk_hw *hw)
268 {
269 	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
270 
271 	clk_hw_unregister(hw);
272 	kfree(osc);
273 }
274 
275 static int clk_sam9x5_slow_set_parent(struct clk_hw *hw, u8 index)
276 {
277 	struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);
278 	void __iomem *sckcr = slowck->sckcr;
279 	u32 tmp;
280 
281 	if (index > 1)
282 		return -EINVAL;
283 
284 	tmp = readl(sckcr);
285 
286 	if ((!index && !(tmp & slowck->bits->cr_oscsel)) ||
287 	    (index && (tmp & slowck->bits->cr_oscsel)))
288 		return 0;
289 
290 	if (index)
291 		tmp |= slowck->bits->cr_oscsel;
292 	else
293 		tmp &= ~slowck->bits->cr_oscsel;
294 
295 	writel(tmp, sckcr);
296 
297 	if (system_state < SYSTEM_RUNNING)
298 		udelay(SLOWCK_SW_TIME_USEC);
299 	else
300 		usleep_range(SLOWCK_SW_TIME_USEC, SLOWCK_SW_TIME_USEC + 1);
301 
302 	return 0;
303 }
304 
305 static u8 clk_sam9x5_slow_get_parent(struct clk_hw *hw)
306 {
307 	struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);
308 
309 	return !!(readl(slowck->sckcr) & slowck->bits->cr_oscsel);
310 }
311 
312 static const struct clk_ops sam9x5_slow_ops = {
313 	.set_parent = clk_sam9x5_slow_set_parent,
314 	.get_parent = clk_sam9x5_slow_get_parent,
315 };
316 
317 static struct clk_hw * __init
318 at91_clk_register_sam9x5_slow(void __iomem *sckcr,
319 			      const char *name,
320 			      const char **parent_names,
321 			      int num_parents,
322 			      const struct clk_slow_bits *bits)
323 {
324 	struct clk_sam9x5_slow *slowck;
325 	struct clk_hw *hw;
326 	struct clk_init_data init;
327 	int ret;
328 
329 	if (!sckcr || !name || !parent_names || !num_parents)
330 		return ERR_PTR(-EINVAL);
331 
332 	slowck = kzalloc(sizeof(*slowck), GFP_KERNEL);
333 	if (!slowck)
334 		return ERR_PTR(-ENOMEM);
335 
336 	init.name = name;
337 	init.ops = &sam9x5_slow_ops;
338 	init.parent_names = parent_names;
339 	init.num_parents = num_parents;
340 	init.flags = 0;
341 
342 	slowck->hw.init = &init;
343 	slowck->sckcr = sckcr;
344 	slowck->bits = bits;
345 	slowck->parent = !!(readl(sckcr) & slowck->bits->cr_oscsel);
346 
347 	hw = &slowck->hw;
348 	ret = clk_hw_register(NULL, &slowck->hw);
349 	if (ret) {
350 		kfree(slowck);
351 		hw = ERR_PTR(ret);
352 	}
353 
354 	return hw;
355 }
356 
357 static void at91_clk_unregister_sam9x5_slow(struct clk_hw *hw)
358 {
359 	struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);
360 
361 	clk_hw_unregister(hw);
362 	kfree(slowck);
363 }
364 
365 static void __init at91sam9x5_sckc_register(struct device_node *np,
366 					    unsigned int rc_osc_startup_us,
367 					    const struct clk_slow_bits *bits)
368 {
369 	const char *parent_names[2] = { "slow_rc_osc", "slow_osc" };
370 	void __iomem *regbase = of_iomap(np, 0);
371 	struct device_node *child = NULL;
372 	const char *xtal_name;
373 	struct clk_hw *slow_rc, *slow_osc, *slowck;
374 	bool bypass;
375 	int ret;
376 
377 	if (!regbase)
378 		return;
379 
380 	slow_rc = at91_clk_register_slow_rc_osc(regbase, parent_names[0],
381 						32768, 50000000,
382 						rc_osc_startup_us, bits);
383 	if (IS_ERR(slow_rc))
384 		return;
385 
386 	xtal_name = of_clk_get_parent_name(np, 0);
387 	if (!xtal_name) {
388 		/* DT backward compatibility */
389 		child = of_get_compatible_child(np, "atmel,at91sam9x5-clk-slow-osc");
390 		if (!child)
391 			goto unregister_slow_rc;
392 
393 		xtal_name = of_clk_get_parent_name(child, 0);
394 		bypass = of_property_read_bool(child, "atmel,osc-bypass");
395 
396 		child =  of_get_compatible_child(np, "atmel,at91sam9x5-clk-slow");
397 	} else {
398 		bypass = of_property_read_bool(np, "atmel,osc-bypass");
399 	}
400 
401 	if (!xtal_name)
402 		goto unregister_slow_rc;
403 
404 	slow_osc = at91_clk_register_slow_osc(regbase, parent_names[1],
405 					      xtal_name, 1200000, bypass, bits);
406 	if (IS_ERR(slow_osc))
407 		goto unregister_slow_rc;
408 
409 	slowck = at91_clk_register_sam9x5_slow(regbase, "slowck", parent_names,
410 					       2, bits);
411 	if (IS_ERR(slowck))
412 		goto unregister_slow_osc;
413 
414 	/* DT backward compatibility */
415 	if (child)
416 		ret = of_clk_add_hw_provider(child, of_clk_hw_simple_get,
417 					     slowck);
418 	else
419 		ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, slowck);
420 
421 	if (WARN_ON(ret))
422 		goto unregister_slowck;
423 
424 	return;
425 
426 unregister_slowck:
427 	at91_clk_unregister_sam9x5_slow(slowck);
428 unregister_slow_osc:
429 	at91_clk_unregister_slow_osc(slow_osc);
430 unregister_slow_rc:
431 	at91_clk_unregister_slow_rc_osc(slow_rc);
432 }
433 
434 static const struct clk_slow_bits at91sam9x5_bits = {
435 	.cr_rcen = BIT(0),
436 	.cr_osc32en = BIT(1),
437 	.cr_osc32byp = BIT(2),
438 	.cr_oscsel = BIT(3),
439 };
440 
441 static void __init of_at91sam9x5_sckc_setup(struct device_node *np)
442 {
443 	at91sam9x5_sckc_register(np, 75, &at91sam9x5_bits);
444 }
445 CLK_OF_DECLARE(at91sam9x5_clk_sckc, "atmel,at91sam9x5-sckc",
446 	       of_at91sam9x5_sckc_setup);
447 
448 static void __init of_sama5d3_sckc_setup(struct device_node *np)
449 {
450 	at91sam9x5_sckc_register(np, 500, &at91sam9x5_bits);
451 }
452 CLK_OF_DECLARE(sama5d3_clk_sckc, "atmel,sama5d3-sckc",
453 	       of_sama5d3_sckc_setup);
454 
455 static const struct clk_slow_bits at91sam9x60_bits = {
456 	.cr_osc32en = BIT(1),
457 	.cr_osc32byp = BIT(2),
458 	.cr_oscsel = BIT(24),
459 };
460 
461 static void __init of_sam9x60_sckc_setup(struct device_node *np)
462 {
463 	void __iomem *regbase = of_iomap(np, 0);
464 	struct clk_hw_onecell_data *clk_data;
465 	struct clk_hw *slow_rc, *slow_osc;
466 	const char *xtal_name;
467 	const char *parent_names[2] = { "slow_rc_osc", "slow_osc" };
468 	bool bypass;
469 	int ret;
470 
471 	if (!regbase)
472 		return;
473 
474 	slow_rc = clk_hw_register_fixed_rate(NULL, parent_names[0], NULL, 0,
475 					     32768);
476 	if (IS_ERR(slow_rc))
477 		return;
478 
479 	xtal_name = of_clk_get_parent_name(np, 0);
480 	if (!xtal_name)
481 		goto unregister_slow_rc;
482 
483 	bypass = of_property_read_bool(np, "atmel,osc-bypass");
484 	slow_osc = at91_clk_register_slow_osc(regbase, parent_names[1],
485 					      xtal_name, 5000000, bypass,
486 					      &at91sam9x60_bits);
487 	if (IS_ERR(slow_osc))
488 		goto unregister_slow_rc;
489 
490 	clk_data = kzalloc(struct_size(clk_data, hws, 2), GFP_KERNEL);
491 	if (!clk_data)
492 		goto unregister_slow_osc;
493 
494 	/* MD_SLCK and TD_SLCK. */
495 	clk_data->num = 2;
496 	clk_data->hws[0] = clk_hw_register_fixed_rate(NULL, "md_slck",
497 						      parent_names[0],
498 						      0, 32768);
499 	if (IS_ERR(clk_data->hws[0]))
500 		goto clk_data_free;
501 
502 	clk_data->hws[1] = at91_clk_register_sam9x5_slow(regbase, "td_slck",
503 							 parent_names, 2,
504 							 &at91sam9x60_bits);
505 	if (IS_ERR(clk_data->hws[1]))
506 		goto unregister_md_slck;
507 
508 	ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, clk_data);
509 	if (WARN_ON(ret))
510 		goto unregister_td_slck;
511 
512 	return;
513 
514 unregister_td_slck:
515 	at91_clk_unregister_sam9x5_slow(clk_data->hws[1]);
516 unregister_md_slck:
517 	clk_hw_unregister(clk_data->hws[0]);
518 clk_data_free:
519 	kfree(clk_data);
520 unregister_slow_osc:
521 	at91_clk_unregister_slow_osc(slow_osc);
522 unregister_slow_rc:
523 	clk_hw_unregister(slow_rc);
524 }
525 CLK_OF_DECLARE(sam9x60_clk_sckc, "microchip,sam9x60-sckc",
526 	       of_sam9x60_sckc_setup);
527 
528 static int clk_sama5d4_slow_osc_prepare(struct clk_hw *hw)
529 {
530 	struct clk_sama5d4_slow_osc *osc = to_clk_sama5d4_slow_osc(hw);
531 
532 	if (osc->prepared)
533 		return 0;
534 
535 	/*
536 	 * Assume that if it has already been selected (for example by the
537 	 * bootloader), enough time has aready passed.
538 	 */
539 	if ((readl(osc->sckcr) & osc->bits->cr_oscsel)) {
540 		osc->prepared = true;
541 		return 0;
542 	}
543 
544 	if (system_state < SYSTEM_RUNNING)
545 		udelay(osc->startup_usec);
546 	else
547 		usleep_range(osc->startup_usec, osc->startup_usec + 1);
548 	osc->prepared = true;
549 
550 	return 0;
551 }
552 
553 static int clk_sama5d4_slow_osc_is_prepared(struct clk_hw *hw)
554 {
555 	struct clk_sama5d4_slow_osc *osc = to_clk_sama5d4_slow_osc(hw);
556 
557 	return osc->prepared;
558 }
559 
560 static const struct clk_ops sama5d4_slow_osc_ops = {
561 	.prepare = clk_sama5d4_slow_osc_prepare,
562 	.is_prepared = clk_sama5d4_slow_osc_is_prepared,
563 };
564 
565 static const struct clk_slow_bits at91sama5d4_bits = {
566 	.cr_oscsel = BIT(3),
567 };
568 
569 static void __init of_sama5d4_sckc_setup(struct device_node *np)
570 {
571 	void __iomem *regbase = of_iomap(np, 0);
572 	struct clk_hw *slow_rc, *slowck;
573 	struct clk_sama5d4_slow_osc *osc;
574 	struct clk_init_data init;
575 	const char *xtal_name;
576 	const char *parent_names[2] = { "slow_rc_osc", "slow_osc" };
577 	int ret;
578 
579 	if (!regbase)
580 		return;
581 
582 	slow_rc = clk_hw_register_fixed_rate_with_accuracy(NULL,
583 							   parent_names[0],
584 							   NULL, 0, 32768,
585 							   250000000);
586 	if (IS_ERR(slow_rc))
587 		return;
588 
589 	xtal_name = of_clk_get_parent_name(np, 0);
590 
591 	osc = kzalloc(sizeof(*osc), GFP_KERNEL);
592 	if (!osc)
593 		goto unregister_slow_rc;
594 
595 	init.name = parent_names[1];
596 	init.ops = &sama5d4_slow_osc_ops;
597 	init.parent_names = &xtal_name;
598 	init.num_parents = 1;
599 	init.flags = CLK_IGNORE_UNUSED;
600 
601 	osc->hw.init = &init;
602 	osc->sckcr = regbase;
603 	osc->startup_usec = 1200000;
604 	osc->bits = &at91sama5d4_bits;
605 
606 	ret = clk_hw_register(NULL, &osc->hw);
607 	if (ret)
608 		goto free_slow_osc_data;
609 
610 	slowck = at91_clk_register_sam9x5_slow(regbase, "slowck",
611 					       parent_names, 2,
612 					       &at91sama5d4_bits);
613 	if (IS_ERR(slowck))
614 		goto unregister_slow_osc;
615 
616 	ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, slowck);
617 	if (WARN_ON(ret))
618 		goto unregister_slowck;
619 
620 	return;
621 
622 unregister_slowck:
623 	at91_clk_unregister_sam9x5_slow(slowck);
624 unregister_slow_osc:
625 	clk_hw_unregister(&osc->hw);
626 free_slow_osc_data:
627 	kfree(osc);
628 unregister_slow_rc:
629 	clk_hw_unregister(slow_rc);
630 }
631 CLK_OF_DECLARE(sama5d4_clk_sckc, "atmel,sama5d4-sckc",
632 	       of_sama5d4_sckc_setup);
633